Ok so my subs sound really bad, they play loud but it is not deep bass, just rattling and noise.

I figured one or both of them may be blown, but when I push on the cone there is no rubbing/scratching noise. The subs look mint. The amp also looks mint. I am pretty sure all wires are connected properly. I have not yet tested them with a multimeter.

What do you guys figure? blown sub? blown amp? bad fuse? bad ground?

 

Answering this really requires more questions......is this a new install or a recent development in an existing system?? Were they working better before you noticed this?? Are there separate terminals for each speaker?

Assuming the box is the right size and type for the subs..... here's a couple of things you can try before you torch them.....

Before you pull them, test them to see if they are in phase.....try hitting them with a 9volt battery.....if they are wired in parallel, when you touch the battery terminals with a wire to the speakers, you should be able to see the cones move....both should be moving in or out at the same time, if not, one is wired out of phase inside the box.....

Metering them separately will tell you if the coils are still OK.

If the amp is a 2 channel and you are using it in stereo, try wiring the drivers in series and bridging the amp....if it sounds better you may have an issue with one channel of the amp......

HTH

 

... so it sounds as if it has lost control correct? Could be a number of potential mechanical issues with the sub (there could be a split in the surround for instance)
or if you are using a common chamber box one of the two going out would sound pretty bad in most situations too
like the red one said you will have to check everything to eliminate it as the source of the problem (verify every amp, every woofer, every wired connection) lets hope the solution is reconnecting a wire and not replacing an amp or sub eh

 

-it is an existing system.
-they used to produce clean bass.
-there are separate terminals for each speaker
-the box is the right size for the speakers
-i am positive the wires inside the box are correct, the positives on the subs run to the positive terminals on the box, and negatives to negatives.
-i used a multimeter and both subs are at 4.0 ohms
-it is a 2-channel amp, how could i test to see if one of the channels is blown?

 

If they are in separate chambers, unhook one at a time and listen for a difference in SQ......common chamber, get the meter back out, unhook both subs and use the meter to check output AC voltage at the amp terminals....they should be very close.

The battery test will confirm phase inside the box without pulling the drivers.

HTH

 

pull the subs out.
check the following:
Spiders - look for seperation from the frame or cracks.
Former to cone joint, may be seperated

 

-they are in a single chamber

-i am not sure what i am doing wrong, i disconnected the subs and inserted the probes on the multimeter into the speaker wire terminals on the amp, and set the multimeter to ac voltage, but both channels read 0.0. is there another way to do this?

-the subs look mint, no separation.

 

meter the subs directly at the speaker

 

I am trying to meter the amp

 

you'll need to check volts at the amp, but that really doesnt help you in any way.
find a test speaker that you can hook up to the amp to test it.
or find an another amp to test your subs